Improvement in siibcthio ftoe-heads



H. J. SMITH. ELECTRIC FUSE HEAD.

Patented June 14, 1870.

Fig.4.

- Inucn/or.

T splice wires. With HENRY JULIUS SMITH, or sosron, nassaonnsnrrs.

Letters Patent No. 104,217, dated June 14, 1870.

W e WROVEMENT IN ELECTRIC FUSE-HEADS.

The Schedule referred to in these Letters Patent and making part of the same.

I, HEN Y J nnrns Smcrn, of Boston, in the State of Massachusetts, have invented an Improvement in Fuse-Heads, .of which the-following is a specification.

The invention consists in so'constructingafnsehead that there is less liability to a communication between the battery-wires outside of the fuse-head,

when used by acareless or ignorant operator, than is;

the case with fuse-heads now in use.

lit also consists in the production of a fuse-head constructed with especial reference to economy in the use of the wires through which the electrical current passes to burst the fuse.

It also consists in certain details ofconstruction hereinafter more particularly set forth.

Fuse-heads are now constructedwith projecting insulated wires, which are twisted or otherwise united into a cord varying from a foot to two yards in length, the cord being cut ofiso as to leave the wires 7 of equal length.

The battery-wires are also made into a cord, and are of equal length.

Tounite the battery-wires with the fuse-wires, the wires of each set or cord are pulled a little way apart, and the insulating covering removed for an inch more or less, from the extremity of each wire. A wire of iach cord is then fastened to a wire of the other cord, but

When the cords thus joined are pulled taut, there is a liability, arising from the uniformity in length of the wires of each cord, to bring the uninsulated places of union into contact with each other. With ignorant or inexperienced operators, this frequently happens. --My invention does away with this ditficulty.

It is the custom of manufacturers to sell fuses made up into bundles or packages, of fuses which have cords of equal length. But, in blasting, the opeiator requires cords or wires of ditferent lengths, especially when communication is to be made between two or more fuse-heads, and he will be under the necessity of purchasing several bundles when he does not-need but one, or he will be obliged tocut olf and lose unnecessary wire, or he will be obliged to my invention, the operator has no cutting off or splicing to do, and he spends no time in selecting a fuse with reference to the length of the cord.

The fuse-cord is usually lost or thrown away after the fuse has been exploded. This loss is saved by the use of my invention, the fuse-head being attached directly to the battery-wires, and

There is a; further advantage in handling and packing my fuse-heads in the factory where they are wires. 1

In the dlawing-- Figurel is an exterior view of the fuse-head. Figure 2 is a sectional view at right angles to the made and sold, since they are not encumbered with view seen in fig. 1.

Figure 3 is a sectional viewiot' the larger cup. Figure 4 is a sectional view of the smaller cup.

The figures are enlarged to three times the actual size of the parts represented.

The shell of the fuse is of wood, .and consists of two cups, the smaller one, marked B in the drawing, when inverted, fitting closely within the other, A, as shown,

The smaller cup is bored out for about half its length, as shown. Two nicks aretheneut upon.opposite sides, deep 'enongh to make small holesat d a, opening into the cup near its bottom, as shown in fig. 4.

Short wires or metallic c, are then push-ed through the holes a a, up to the eves.

These wires are fastened into the cup by driving a plug, 0, between them, and they are bent over the plug, as shown, so as to come within a short distance of each other. The plug is driven to the bottom of the cup, so that there is no communication between the holes a a.

The remaining pound, and the small cup is inverted and driven into the large cup, which has previously been. filled with the same or other explosive compound. T

A modification of my invent-ion may be made from a fuse as ordinarily constructed, of a cup and cylinder, by cutting ofl the wires very near to the mouth of the cylinder.

In such case, after the insulating covering is stripped from the end of the wires, thc uncovered ends should be kept part by a wooden wedge,-diiven into the cylinder between them, the head of the wedge remaining outside of the cylinder, being high enough and wide enough to serve as a shield between the said ends, and between the exposed ends of the battery wires, to prevent electiica outside of the fuse-head.

To explode the fuse-head, a wire cord is attached to each eye 0' e.

The most ignorant operator will do this without bringing the exposed extremities of the wires into contact, since the insulating covering is not readily removed from more than rather less than an inch ot the wire. The rest of the operation is obvious.

I claimof the batteryplatcsu 6, having eyes a" space within "the small cup is then filled with electrical priming, or a fulminating 001111 1 comnmnication 1. A fuse-head having plates 01: wires extending 2b A fuse-hem], having plates or wires provided from the magazine or ehamber to. the outside, of with eyes, substantially as described, for the purpose such length and in such manner that communication described. 1

between them, and communication between the ex- H. JULIUS SMITH. posed ends of the battery-wires to which they are attached, is prevented by the interposition of the body Witnesses:

of the fuse-heed, or by the interposition of a'wedge,' WILLIAMLW. SWAN,

substantially as described. I Ones. P, 901mm. 

